This case study focuses on teachers' professional development in NanoScience and nanoTechnology (NST). In the context of a Community of Learners (CoL), in-service teachers in collaboration with science education researchers, nanoscience researchers and experts from science museums, developed a teaching module. This module integrates NST topics along with aspects of science communication, i.e. development of science exhibits and socio-scientific issues, e.g. ethics regarding the research in this field. The data were gathered over 1-year period by using video recordings and interviews. The Interconnected Model of Professional Growth was used to study the processes that support teachers' professional change in this context, as they are elicited from their interactions in the CoL. Our findings indicate that the dynamic of teachers' interactions with colleagues and the mediating processes that impact on their professional learning, are crafted on the basis of the emerged challenges in each phase of module's design and development. These findings give an insight on teachers' professional learning as they transfer their professional knowledge regarding scientific topics which are innovative to them, i.e. NST, into their teaching practice. In this respect, this study contributes to research literature relevant to teachers' professionalisation in order to implement innovations in the classroom.